How Does Red Meat Cause Colon Cancer?

How Can You Decrease Your Risk Of Colon Cancer? 

Author: Dr. Stephen Chaney

Grilled HamburgersBoth red meat and processed meat consumption are associated with increased risk of colon cancer. But the strength of that association differs between the two.

Processed meat has been classified as a carcinogen by the IARC*, indicating the evidence that processed meat causes colon cancer is definitive. Red meat, on the other hand, has been classified as a probable carcinogen by the IARC*. That means the evidence that red meat causes colon cancer is strong, but not definitive.

*[In case you were wondering, the IARC (International Agency for Research on Cancer) is an international agency charged by the WHO to, among other things, determine the risk of cancer from various foods, industrial chemicals, and environmental pollutants.]

As I said above, red meat consumption is associated with increased risk of colon cancer. But…

  • Not all studies agree (more about that later), and…
  • Association doesn’t prove cause and effect. It could be some other characteristic of red meat eaters that increases their risk of colon cancer.
  • Until recently we had no clear idea of how red meat might cause colon cancer.

Several mechanisms have been proposed. I will discuss each mechanism and ways to reduce the risk of colon cancer by that mechanism:

#1: When fat and juices from the meat drip onto an open flame, carcinogenic polyaromatic hydrocarbons (PAHs) Barbecue Gatheringare formed that stick to the surface of the meat. PAHs can be metabolized to cancer causing chemicals in our body.

  • PAH formation can be reduced by marinating the meat prior to cooking or by using cooking techniques that don’t involve an open flame.
  • PAH formation can be reduced, but not eliminated, by lower fat meat choices, such as grass-fed beef.
  • High fiber diets reduce exposure to PAHs by binding to them and flushing them through the intestine.
  • Cruciferous vegetables block the conversion of PAHs to cancer causing chemicals in our body.

#2: When red meats are cooked at high temperatures, amino acids in the meat combine with creatine, which is found in all red meats, to form heterocyclic amines (HCAs). HCAs can also be metabolized to cancer causing chemicals in our body.

  • HCA formation can be reduced by cooking the meat at lower temperatures.
  • Grass-fed beef does not reduce HCA formation because this mechanism is not dependent on the fat content of the meat.
  • High fiber diets and cruciferous vegetables reduce the danger of HCAs by the same mechanisms as for PAHs.

#3: The nitrates and nitrites used as preservatives in many processed meats react with amino acids from the meat to form carcinogenic N-nitrosamines in our intestines.

  • Antioxidant-rich fruits and vegetables can divert nitrates and nitrites into an alternative pathway that coverts them into nitric oxide, which is beneficial to our bodies. I have discussed this in a previous issue of “Health Tips From the Professor”.

#4: Heme, which is found in all red meats, combines with amino acids in the meat to form carcinogenic N-nitrosamines and similar N-nitroso compounds in our intestines.

  • This mechanism is inherent in all red meats and cannot be eliminated by choosing grass-fed beef or cooking at lower temperatures.
  • The formation of N-nitroso compounds from red meat appears to be carried out by gut bacteria. We know that meat eaters and vegetarians have very different populations of gut bacteria, but we don’t know whether this influences N-nitroso formation.

Mechanism #4 (formation of N-nitroso compounds from heme-containing red meat in our intestines) is the one I will be discussing in this article. But first, it’s time for Metabolism 101.

Metabolism 101: Why Should We Fear N-Nitroso Compounds?

ProfessorSimply put, N-nitroso compounds react with our DNA. They transfer methyl and ethyl groups to the nucleotides that make up our DNA sequence. The general term for these reactions is alkylation of the DNA.

  • In some cases, this causes the alkylated nucleotides to miscode during DNA replication. This can lead to cancer causing mutations.
  • In other cases, this causes genes to be permanently turned on or off.

To understand why this is a problem, you need to know a bit about cancer cell biology.

  • We have certain genes called “oncogenes”. These are genes that turn on processes like cell division. Normally these genes are tightly regulated so that cell division only occurs when it is needed. When these genes are permanently turned on, unregulated, continuous cell division occurs. In short, the cell becomes a cancer cell.
  • We have other genes called “tumor suppressor genes”. These are genes that do things like shutting down cell division when it is not needed. When these genes are permanently turned off, unregulated cell division can occur.

With this in mind, let us review what we know about red meat and colon cancer:

  • Red meat consumption is associated with increased risk of colon cancer.
  • Red meat consumption is also associated with increased concentrations of N-nitroso compounds in the colon. Studies also show:
  • The formation of N-nitroso compounds correlates with the heme content of the meat.
  • The formation of N-nitroso compounds in the colon is dependent on certain strains of gut bacteria.
  • The formation of N-nitroso compounds is reduced by diets high in fiber. It is likely this is because high fiber diets influence the types of bacteria in the colon, but that has not been proven yet.

What is missing is evidence that colon cancer cells contain the kind of DNA modifications (DNA alkylation) caused by N-nitroso compounds. That is what the current study (C Gurjao et al, Cancer Discovery, published online June 17, 2021) was designed to test.

How Was This Study Done?

Clinical StudyOne reason previous studies had not been able to demonstrate a clear correlation between red meat consumption and DNA modifications was that the studies were too small to obtain statistically significant results.

So, the authors of this study combined data from women in the Nurses’ Health Study, the Nurses’ Health Study II, and men in the Health Professionals Follow-Up Study. There were over 238,130 women and 51,529 men in these three studies.

None of the participants had cancer at the time they entered the studies. The participants were followed for at least 27 years. During that time 4855 participants developed colon cancer.

At the beginning of each study and every 4 years later the participants were asked to fill out a food frequency questionnaire to collect information about their usual diet over the past year. Validation studies showed that the diets of the participants changed little over the interval of the studies.

The participants in these studies were sent follow-up questionnaires every two years to collect information on lifestyle and newly diagnosed diseases like colon cancer.

For those who developed colon cancer, their medical records were reviewed to collect data on tumor size, tumor location, and disease stage.

The diagnoses of colon cancer often involves removing tissue from the cancer and from surrounding normal tissue and putting it in formalin-fixed paraffin-embedded tissue blocks. These were collected, and the DNA was extracted and sequenced to determine the extent and genetic location of alkylated DNA sequences.

How Does Red Meat Cause Colon Cancer?

colon cancerThis study measured the effect of red meat consumption on the extent and location of what the authors called “alkylation signatures”, which refers to the kinds of DNA modifications caused by N-nitroso compounds. Here is what they found:

  • Red meat consumption was positively associated with an increase in alkylation signatures caused by N-nitroso compounds in tumor tissue from patients with colon cancer.
    • This was true for both processed and unprocessed red meat.
    • There was no difference between men and women after adjusting for differences in red meat intake.
    • White meat (chicken and fish) did not cause an increase in alkylation damage in colon cells.
  • More importantly, there was an inverse association between alkylation damage in the tumor tissue and patient survival. Simply put, high levels of alkylation damage were associated with short survival times.

Previous studies have shown that processed red meat consumption was associated with increased levels of N-nitroso compounds and an increased risk of colon cancer in the distal colon.

  • This study showed colon cancer patients who had been consuming processed red meats had higher alkylation damage in tumors in the distal colon.

Previous studies have shown that certain oncogenes (genes that drive the conversion of normal cells to cancer cells) are activated in colon cancer cells and this activation is associated with alkylation damage to their DNA.

  • This study showed that tumors with activated oncogenes were enriched with the alkylation signature characteristic of N-nitroso compounds.

I realize this study is highly technical. It is not easy to understand, so let me simplify it.

  • Previous studies have shown that red meat consumption is associated with an increased risk of colon cancer.
  • Previous studies have also shown that red meat consumption is associated with an increased concentration of carcinogenic N-nitroso compounds in the colon.
  • This study shows that red meat consumption is associated with the kind of DNA damage caused by N-nitroso compounds in colon tumor cells. More importantly, this is the kind of damage that can lead to cancer-causing mutations. In addition:
    • The DNA damage occurs in the exact location of the colon predicted from earlier studies.
    • The DNA damage occurs in genes known to drive the conversion of normal colon cells to cancer cells.

In short, this study provides a plausible mechanism for the effect of red meat consumption on increased risk of colon cancer. It shows how red meat can cause colon cancer.

“In the words of the authors, “Our study has leveraged a comprehensive dataset with repeated dietary measures over years…and [DNA sequencing] on a large collection of colorectal tumors. It provides unique evidence supporting the direct impact of dietary behaviors on colorectal carcinogenesis…”

How Can You Decrease Your Risk Of Colon Cancer?

Steak SaladWhen this study is combined with previous studies, it provides a clear explanation of how red and processed meats can cause colon cancer. And, unfortunately, grass-fed beef is not a “Get Out Of Jail Free” card. This mechanism is equally applicable to grass-fed beef and conventionally raised beef.

Does this mean you need to become a vegan? While I have nothing against veganism, the answer appears to be no. As I discussed above whole, unprocessed plant foods are the antidote to the carcinogenic compounds formed from red meat. This is due to:

  • Their fiber, which sweeps some carcinogens out of the intestine before they can be absorbed.
  • Their antioxidants, which prevent some carcinogens from being formed.
  • Their phytonutrients, which block the activation of some carcinogens.
  • The friendly gut bacteria they support, which displace the bad bacteria that form some carcinogen precursors in the intestine.

The good news is that some red meat may be OK in the context of a primarily plant-based diet. For example, 3 ounces of red meat in a green salad or stir fry is less likely to increase your risk of colon cancer than an 8-ounce steak and fries.

The bad news is this is why not all studies have shown an association of red meat consumption and increased risk of colon cancer. Unfortunately, far too many of these studies have ignored other components of the diet.

The Bottom Line

A recent study looked at the effect of red meat consumption on DNA modifications in colon cells that are associated with the conversion of normal cells to cancer cells. It is a highly technical study, but the simplified version is:

  • Previous studies have shown that red meat consumption is associated with an increased risk of colon cancer.
  • Studies have also shown that red meat consumption is associated with an increased concentration of carcinogenic N-nitroso compounds in the colon.
  • This study shows that red meat consumption is associated with the kind of DNA damage caused by N-nitroso compounds in colon tumor cells – the kind of damage that can lead to cancer-causing mutations. In addition:
    • The DNA damage occurs in the exact location of the colon predicted from earlier studies.
    • The DNA damage occurs in genes known to drive the conversion of normal colon cells to cancer cells.

In short, this study provides a plausible mechanism for the effect of red meat consumption on increased risk of colon cancer. It shows how red meat can cause colon cancer.

“In the words of the authors, “Our study has leveraged a comprehensive dataset with repeated dietary measures over years…and [DNA sequencing] on a large collection of colorectal tumors. It provides unique evidence supporting the direct impact of dietary behaviors on colorectal carcinogenesis…”

For more details about this study and how you can eat red meat and still reduce your risk of colon cancer, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Best Way To Reduce Risk Of Breast Cancer

What Does The American Cancer Society Say About Reducing Breast Cancer Risk? 

Author: Dr. Stephen Chaney

breast cancerBreast cancer is a scary disease. The American Cancer Society tells us:

  • 281,000 women will be diagnosed with invasive breast cancer in 2021.
  • 43,000 women will die from breast cancer in 2021.
  • The good news is that both prevention and treatment of breast cancer have gotten much better:
    • The 5-year survival rate is 90%.
    • The 10-year survival rate is 84%.
    • For women over 50 the death rate has decreased by 1%/year between 2013 and 2018 (mainly due to recognition that hormone replacement therapy is a risk factor for breast cancer).
  • The bad news is:
    • The cost of breast cancer treatment can range from $50,000 to over $180,000.
    • The side effects of breast cancer treatment can be brutal.
      • For example, there is an effective treatment to prevent breast cancer recurrence for some forms of breast cancer, but many women discontinue the treatment after a few years because of the side effects.

So, wouldn’t it be wonderful if there were some simple changes you could make that would dramatically reduce your risk of developing breast cancer in the first place? There are lots of options for reducing your risk of developing breast cancer, but which one(s) should you choose?

  • Dr. Strangelove and his friends are only too happy to recommend their favorite potion, food, or diet.
  • There are long lists of foods you should avoid if you want to reduce your risk of breast cancer.
  • There are also lists of harmful chemicals in cleaners and other household products that you should avoid.

It can become confusing. It can become overwhelming. It would be easy to just throw up your hands and say, “I give up. I don’t know what to do.”

You may be thinking, “Why doesn’t someone simplify things by identifying the top few lifestyle changes that are most effective for reducing my risk of developing breast cancer?”

It turns out someone has. Today I will share two recent studies that have identified the top 6 strategies for reducing your risk of breast cancer, and I have ranked them from 1 to 6 in order of effectiveness.

What Is The Best Way To Reduce Risk Of Breast Cancer?

AwardThe first study (RM Tamimi et al, American Journal of Epidemiology, 184: 884-893, 2016 was designed to identify the major modifiable risk factors for invasive, postmenopausal breast cancer (The term “modifiable risk factors” refers to those risk factors that are under your control.

The study utilized data collected from the Nurses’ Health Study between 1980 and 2010. During that time 8,421 cases of invasive breast cancer were diagnosed in 121,700 postmenopausal women in the study. The study looked at the effect of nonmodifiable and modifiable risk factors on the development of invasive breast cancer in these women.

  • Nonmodifiable risk factors included current age, age at which menstruation began, height, age of first birth, number of births, weight at age 18, family history of breast cancer, and prior benign breast disease.
  • Modifiable risk factors included weight change since age 18, alcohol consumption, physical activity level, breastfeeding, and postmenopausal hormone therapy use.

Here were the results from the study:

  • All the risk factors included in this study accounted for 70% of the risk of developing invasive breast cancer in postmenopausal women.
  • Modifiable risk factors accounted for 34.6% of the risk of developing invasive breast cancer in postmenopausal women.

When they analyzed the effect of modifiable risk factors on the risk of developing invasive breast cancer separately:

  • 44 pounds of weight gain since age 18 increased the risk by 50%.
  • Postmenopausal hormone replacement use increased the risk by 35%.
  • More than one alcoholic beverage/day increased the risk by 32%.
  • Low physical activity increased the risk by 7%.
  • Lack of breastfeeding increased the risk by 5%.

What About The Effect Of Diet On Breast Cancer Risk?

You may be wondering, “What about the effect of a healthy diet on my risk developing invasive breast cancer?” Unfortunately, the study I described above completely disregarded the effect of diet on breast cancer risk.

However, the second study (MS Farvid et al, International Journal of Cancer, 144: 1496-1510, 2019) I will discuss today partially addresses this issue. It uses the same database as the first study and looks at the effect of fruit and vegetable consumption on the risk of developing invasive breast cancer.

When this study compared high versus low intake of fresh fruits and vegetable on the risk of developing invasive breast cancer:

  • Women eating >5.5 servings/day of fruits and vegetables had a 11% lower risk than women consuming ≤2.5 servings/day.
  • Women consuming >2.5 servings/day of fruit had a 9% lower risk than women consuming ≤0.5 servings/day.
  • Women consuming >4.5 servings/day of vegetables had a 9% lower risk than women consuming ≤0.5 servings/day.

While all fresh fruits and vegetables contributed to this effect:

  • The most protective fruits were berries and cantaloupe & melons.
  • The most protective vegetables were yams & sweet potatoes, green leafy vegetables (such as kale, mustard greens, and chard), and cruciferous vegetables (such as Brussels sprouts).

The authors concluded, “Our findings support that higher intake of fruits and vegetables, and specifically cruciferous and yellow/orange vegetables, may reduce the risk of breast cancer, especially those that are more likely to be aggressive tumors.”

Now we are ready to answer your question, “Which lifestyle changes are most effective for reducing your risk of developing breast cancer?” If we combine the two studies and rank order the modifiable risk factors, it would look like this.

#1: Minimize weight gain during your adult years.

#2: Don’t use postmenopausal hormone replacement therapy unless absolutely necessary.

#3: Drink little or no alcohol.

#4: Eat a healthy diet with lots of fresh fruits and vegetables.

#5: Be physically active.

#6: Breastfeed when possible.

What Does The American Cancer Society Say About Reducing The Risk Of Breast Cancer?

American Cancer SocietyThe advice of the American Cancer Society is remarkably similar. Here are their recommendations:

  1. Get to and stay at a healthy weight.

After menopause, most of your estrogen comes from fat tissue. Having more fat tissue increases the amount of estrogen your body makes, raising your risk of breast cancer. Also, women who are overweight tend to have higher levels of insulin. Higher insulin levels have also been linked to breast cancer.

If you are already at a healthy weight, stay there. If you are carrying extra pounds, try to lose some. Losing even a small amount of weight can also have other health benefits and is a good place to start.

3) Be physically active and avoid time spent sitting.

Current recommendations are to get at least 150-300 minutes of moderate intensity or 75-150 minutes of vigorous intensity activity each week. Getting to or exceeding 300 minutes is ideal.

In addition, you should limit sedentary behavior such as sitting, lying down, watching TV, and other forms of screen-based entertainment. This is especially important if you spend most of your working day sitting.

3) Follow a healthy eating plan.

A healthy eating pattern includes a variety of vegetables, fiber-rich legumes (beans and peas), fruits in a variety of colors, and whole grains. It is best to avoid or limit red and processed meats, sugar-sweetened beverages, highly processed foods, and refined grain products. This will provide you with key nutrients in amounts that help you get to and stay at a healthy weight.

4) It is best not to drink alcohol.

Research has shown that drinking any alcohol increases the risk of breast cancer. If you choose to drink alcohol, the American Cancer Society recommends that women have no more than 1 alcoholic drink on any given day. A drink is 12 ounces of regular beer, 5 ounces of wine, or 1.5 ounces of hard liquor.

5) Think carefully about using hormone replacement therapy.

Studies show that HRT using a combination of estrogen and progestin increases the risk of breast cancer. This combination can also lead to increased breast density making it harder to find breast cancer on mammogram.

Talk with your doctor about all the options to control your menopause symptoms, including the risks and benefits of each. If you decide to try HRT, it is best to use it at the lowest dose that works for you and for as short a time as possible.

The Bottom Line

Breast cancer is a scary disease. The good news is that detection and treatment of breast cancer has improved over the past decade. The bad news is that treatment is expensive, and the side effects can be brutal.

There are lots of options for reducing your risk of developing breast cancer, but which one(s) should you choose?

  • Strangelove and his friends are only too happy to recommend their favorite potion, food, or diet.
  • There are long lists of foods you should avoid if you want to reduce your risk of breast cancer.
  • There are also lists of harmful chemicals in cleaners and other household products that you should avoid.

It can become confusing. It can become overwhelming. It would be easy to just throw up your hands and say, “I give up. I don’t know what to do.”

You may be thinking, “Why doesn’t someone simplify things by identifying the top few lifestyle changes that are most effective for reducing my risk of developing breast cancer?”

It turns out someone has. Today I will share two recent studies that have identified the top 6 strategies for reducing your risk of breast cancer, and I have ranked them from 1 to 6 in order of effectiveness in the article above.

For more details about these studies, my ranking of the top 6 strategies for reducing your risk of breast cancer, and the American Cancer Society recommendations, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Would You Like Cancer With That Burger?

Enjoy Your Cookouts Without Increasing Cancer Risk 

Author: Dr. Stephen Chaney

Barbecue GatheringIt is July and backyard cookouts are in full swing. One question that you probably won’t hear from your host or hostess is “Would you like cancer with that burger?” But perhaps that is exactly the question they should be asking.

  • You probably didn’t really want to know that when fat from the meat hits the hot coals, carcinogens form that are deposited on the meat.
  • You probably also didn’t want to know that when you cook meat to high temperatures the amino acids in the meat combine to form cancer causing substances.
  • And you really didn’t want to know that a recent study showed that men who consume well-done red meat were ~60% more likely to develop advanced prostate cancer.

Would You Like Cancer With That Burger?

Grilled HamburgersA recent study compared 531 people ages 40-79 who had recently been diagnosed with advanced prostate cancer with 527 matched controls. Both groups were asked about their dietary intake of meats, usual meat cooking methods and doneness of the meat.

The results were quite striking:

  • Increased consumption of hamburgers was associated with a 79% increased risk of advanced prostate cancer.
  • Increased consumption of processed meat was associated with a 57% increased risk of advanced prostate cancer.
  • Grilled red meat was associated with a 63% increased risk of advanced prostate cancer.
  • Well done red meat was associated with a 52% increased risk of advanced prostate cancer.

However, those percentages are a little bit difficult to compare, because “increased consumption” was defined relative to what the usual consumption or cooking practice was. So put another way, weekly consumption of…

  • 3 or more servings of red meat or…
  • 5 or more servings of processed meat or…
  • 1 or more servings of grilled or well-done red meat…

…were associated with a 50% increased risk of advanced prostate cancer.

In contrast, consumption of white meat was not associated with increased prostate cancer risk, no matter what the cooking method was used.

Enjoy Your Cookouts Without Increasing Cancer Risk

Grilled Chicken With VeggiesOur local newspaper recently carried some tips by Dr. Denise Snyder from the Duke University School of Nursing on how you could reduce the risk of giving your guests cancer the next time you are the chef at your backyard cookout.

Here are her suggestions:

  • Grill fruits and vegetables instead of meat. That was her idea, not mine. My editorial comment would be that grilling white meat (fish or chicken) may also be OK.
  • Use the lowest temperature that will cook your food thoroughly and keep the grill rack as high as possible.
  • Use a meat thermometer so that you can make sure that as soon as the meat is thoroughly cooked you remove it from the grill. We usually overcook the meat to make sure that it is done.
  • Shorten your grill time by microwaving the meat first, using thinner leaner cuts of meat or cutting up the meat and making kabobs.
  • Trim as much fat from the meat as possible before you cook it.
  • Line your grill rack with aluminum foil poked with holes. This allows the fat to drip down but minimizes the exposure of the meat to the carcinogens formed when the fat hits the coals.
  • Marinate your meats before grilling. That has been shown to reduce the formation of cancer-causing chemicals.
  • And, of course, avoid processed meats like hot dogs and sausage completely because they have been shown to increase the risk of cancer and diabetes no matter how they are cooked.

So, here’s to a healthier cookout. Bon appétit!

The Bottom Line

  1. You already knew that red meat and processed meats may increase your risk of cancer, but how you cook your red meat also matters. Grilling your meat and/or cooking it until it is well done appear to significantly increase your risk of developing advanced prostate cancer.

2) In contrast, consumption of white meat was not associated with increased cancer risk, no matter what the cooking method was used.

3) I have included several tips on how you can reduce the cancer risk associated with grilling red meats in the article above so you can enjoy both your cookouts and your health.

For more details about this study and what it means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Which Foods Should I Avoid?

What Is Nutritionism?

In Defense Of FoodRecently, I have been reading Michael Pollan’s book “In Defense of Food”. Yes, I know the book has been around for a long time. Normally I read the scientific literature rather than popular health books. However, in the past few weeks I have had a lot more time to read books, so I decided to read this one.

Some of the things he says are “off the wall”. As he readily admits, he isn’t a scientist or a medical doctor. However, a lot of what he says is “right on”. He echoes many of the things I have been talking about for years. But he does a masterful job of pulling everything together into a framework he calls “nutritionism”.

If you have a chance, I highly recommend that you read his book.

I will briefly summarize his discussion of nutritionism below. I will also share some scientific support for what he is saying. Finally, I will close by sharing what the Bible says on the subject.

What Is Nutritionism?

Low Fat LabelSimply put, nutritionism is the belief that we can understand food solely in terms of its nutritional and chemical constituents and our requirements for them. I use the term “belief” purposely. As Michael Pollan puts it: “As the ‘-ism’ suggests, nutritionism is not a scientific subject, but an ideology.”

What Michael Pollan is referring to is taking food constituents like saturated fats, cholesterol, sugar, carbohydrates, polyunsaturated fats, monounsaturated fats, fiber, antioxidants, and probiotics and labeling them as either “good” or “bad”.

As he points out, that leads to debacles like the creation of margarine as a substitute for butter. Of course, everyone reading this article knows that we subsequently found out that the trans fat in margarine was worse for us than the saturated fat in butter. He offers many other examples like this.

He also points out that the nutritionism concept has given free rein to the food industry to replace whole foods with processed foods that are cholesterol-free, sugar-free, low-fat, low-carb, or high in fiber, omega-3s, etc. He says that these foods are seldom healthier than the foods they replace. I agree.

Finally, he points out that the scientific support for the classification of individual ingredients or foods as “good” or “bad” is weak. That’s because when scientists design a study that removes a chemical constituent or a food from the diet, they have to replace it with something. And what they replace it with determines the outcome of the study. I give some examples of this in the next section.

The essence of Michael Pollan’s message is:

  • The effect of an individual nutrient or chemical constituent on your health depends on the food it is found in. Forget the fancy nutrition labels. Whole foods are almost always healthier than processed foods.
  • The effect of a food or food constituent on your health also depends on your overall diet. We should be thinking about healthy diets rather than the latest “magical” or “forbidden” food.

I will discuss these points below.

Which Foods Should I Avoid?

Question MarkNow, let’s get to the question, “Which Foods Should I Avoid?” If we are talking about whole foods, the short answer is “None”. As I said in my book, “Slaying The Food Myths”, “We have 5 food groups for a reason”.

For example, if we are talking about plant foods, each plant food group:

  • Has a unique blend of vitamins and minerals.
  • Has a unique blend of phytonutrients.
  • Has a unique blend of fiber.
  • Supports the growth of a unique combination of beneficial gut bacteria.
  • Dr Strangelove and his friends are telling you to eliminate whole grains, fruits, and legumes (beans) from your diet. Recent studies suggest that might not be a good idea. Here is one example.

If we are talking about animal foods, each animal food group:

  • Has a unique blend of vitamins and minerals.
  • May have unique components that are important for our health. [Note: This is an active area of research. Theories have been proposed for which components in animal foods may be important for our health, but they have not been confirmed.]
  • Vegan purists will tell you that you have no need for meat and dairy foods. Recent studies suggest otherwise. Here is one example.

With that as background, let’s turn our attention to nutritionism and look at some of science behind claims that certain food components are either good for us or bad for us.

Saturated Fat. Saturated fat is the poster child for nutritionism.lowfat

First, we were told by the American Heart Association and other health organizations that saturated fat was bad for us. Recently Dr. Strangelove and his friends are telling us that saturated fat is good for us. Instead of limiting saturated fat, we should be limiting carbs by cutting out fruits, whole grains, and legumes. Both cite clinical studies to support their claims. How can this be?

Perhaps a little history is in order. When the American Heart Association recommended that we decrease intake of saturated fat, they were envisioning that we would replace it with monounsaturated and polyunsaturated fat in the context of a healthy diet of fruits, vegetables, whole grains, and legumes. That never happened.

Big Food quickly realized that if the American public were to follow the AHA guidelines, it would be disastrous for their bottom line. So, they sprang into action. They mixed sugar, white flour, and a witch’s brew of chemicals to create highly processed, low fat “foods”. Then they told the American public, “Don’t worry. You don’t have to give up your favorite foods. We have created low fat alternatives.”

This is the essence of what Michael Pollan refers to as nutritionism. By marketing their fake foods as low fat Big Food created the halo of health. In fact, Big Food’s fake foods were less healthy than the foods they replaced. Americans got fatter and sicker.

Now let’s look at the conflicting claims that saturated fat is bad for us or good for us. How can clinical studies disagree on such an important question? The answer is simple. It depends on what you replace it with. You need to consider saturated fat intake in the context of the overall diet.

I discussed this in a previous issue of “Health Tips From the Professor”, but let me summarize it briefly here. The American Heart Association tells us that replacing half of the saturated fat in a typical American diet with:

  • Trans fats, increases heart disease risk by 5%.
  • Refined carbohydrates and sugars (the kind of carbohydrates in the typical American Diet), slightly increases heart disease risk.
  • Complex carbohydrates (whole grains, fruits & vegetables), decreases heart disease risk by 9%.
  • Monounsaturated fats (olive oil & peanut oil), decreases heart disease risk by 15%.
  • Polyunsaturated fats (vegetable oils and fish oil), decreases heart disease risk by 25%.
  • Unsaturated fats in the context of a Mediterranean diet, decreases heart disease risk by 45%.

My advice: Saturated fat is neither good for you nor bad for you. A little bit of saturated fat in the context of a healthy diet is fine. A lot of saturated fat in the context of an unhealthy diet is problematic.

fatty steakRed Meat. Is red meat bad for you? Like saturated fat, it depends on the amount of red meat and the overall diet. I covered this in detail in “Slaying The Food Myths”, but let me summarize briefly here:

According to the World Health Organization, red meat is a probable carcinogen. If we look at the postulated mechanisms by which it causes cancer, they can be mostly neutralized by components of various plant foods.

My advice: An 8-ounce steak with fries and a soda is probably bad for you. Three ounces of that same steak in a green salad or stir fry may be good for you.

I should make one other point while I am on the topic. Dr. Strangelove and his friends have been telling you that grass-fed beef is better for you than conventionally raised beef. Once again, that is nutritionism.  Grass-fed beef is lower in saturated fat and high in omega-3s than conventionally raised beef. That may be better for your heart, but it has no effect on the cancer-causing potential of red meat. It doesn’t give the license to eat 8-ounce steaks on a regular basis. You still want to aim for 3-ounces of that grass-fed beef in a green salad or stir fry. 

High-Fructose Corn Syrup. This one seems to be on everyone’s “naughty list”. You are being told to read labels, and if the food has high-fructose corn syrup on the label, put it back on the shelf. But is that good advice?

It turns out that all the studies on the bad effects of high-fructose corn syrup have been done with sodas and highly processed foods. This should be your first clue.

Of course, as soon as high-fructose corn syrup gained its “bad” reputation, Big Food started replacing it with Sugar Comparisons“heathier” sugars. Does that make those foods healthier?

The answer is a clear “No”. Both chemically and biologically, high-fructose corn syrup is identical to sucrose (table sugar), honey, molasses, maple syrup, coconut sugar, date sugar, or grape juice concentrate. Agave sugar is even higher in fructose than high-fructose corn syrup. This is your second clue.

Substituting these sugars for high-fructose corn syrup doesn’t turn sodas and processed foods into health foods. This is nutritionism at its worst.

My advice: Forget reading the label. Forget trying to avoid foods with high-fructose corn syrup. Avoid sodas and processed foods instead.

Sugar. Once the public started to realize that natural sugars in processed foods were just as bad for us as high-fructose corn syrup, sugars became “bad”. We were told to avoid all foods containing sugar in any form. In fact, we were told we needed to become “label detectives” and recognize all the deceptive ways that sugar could be hidden on the label.

Apple With Nutrition LabelI have discussed this in detail in a previous issue of “Health Tips From The Professor”.

Let me just summarize that article with one quote, “It’s not the sugar. It’s the food. There is the same amount and same types of sugar in an 8-ounce soda and a medium apple. Sodas are bad for you, and apples are good for you.” If you are wondering why that is, I have covered it in another issue of “Health Tips From the Professor”.

Before leaving this subject, I should mention that nutritionism has risen its ugly head here as well. Big Food has struck again. They have replaced sugar with a variety of artificial sweeteners.

Once again, nutritionism has failed. Those artificially sweetened sodas and processed foods are no healthier and no more likely to help you keep the weight off than the sugar-sweetened foods they replace. I have covered the science behind that statement in several previous issues of “Health Tips From the Professor”. Here is one example.

My advice: Forget about sugar phobia. You don’t need to become a label detective. Just avoid sodas, sugar-sweetened beverages, and sweet processed foods. Get your sugar in its natural form in fruits and other whole foods.

low carb dietCarbs. Dr. Strangelove and his friends are now telling you that you need to avoid all carbs. That is pure nutritionism. Carbs are neither good nor bad. It depends on the type of carb and what you replace it with.

Once again, clinical studies have given conflicting outcomes. Each side of the carbohydrate debate can provide clinical studies to support their position. How can that be? The answer is simple. It depends on what assumptions went into the design of the clinical studies. I have written several articles on this topic in “Health Tips From the Professor”, but let me give you one example here.

In this example, I looked at two major studies. The PURE (Prospective Urban Rural Epidemiology) study included data from 135,000 participants in 18 countries. In this study, the death rate decreased as the % carbohydrate in the diet decreased. The low-carb enthusiasts were doing a victory dance.

However, it was followed by a second, even larger study. The ARIC (Atherosclerosis Risk In Communities) study included 432,000 participants from even more countries. In this study, the death rate decreased as the % carbohydrate decreased to about 40%. Then a curious thing happened. As the % carbohydrate in the diet decreased further, the death rate increased.

How can you explain this discrepancy? When you examine the PURE study:

  • The % carbohydrate only ranged from 70% to 40%.
  • The data for the PURE study was obtained primarily with third world countries. That is an important distinction because:
    • In those countries, it is primarily the well to do that can afford sodas, processed foods, and meat.
    • The poor subsist on what they can grow and inexpensive staples like beans and rice.
  • Simply put, in the PURE study, the type of carbohydrate changed as well as the amount of carbohydrate.
    • At the highest carbohydrate intakes, a significant percentage of the carbohydrate came from sugar and refined grains.
    • At the lowest carbohydrate intakes, most of the carbohydrate intake came from beans, whole grains, and whatever fruits and vegetables they could grow.

When you examine the ARIC study:how much carbohydrates should we eat aric

  • The % carbohydrate ranged from 70% to 20%.
  • The ARIC study added in data from the US and European countries. That is an important distinction because:
    • Low carb diets like Atkins and Keto are popular in these countries. And those are the diets that fall into the 20-40% carbohydrate range.
    • Most people can afford diets that contain a lot of meat in those countries.
  • Simply put, at the lower end of the scale in the ARIC study, people were eating diets rich in meats and saturated fats and eliminating healthy carbohydrate-containing foods like fruits, whole grains and legumes.

My advice: The lesson here is to avoid simplistic nutritionism thinking and focus on diets rather than on foods. When you do that it is clear that carbs aren’t bad for you, it’s unhealthy carbs that are bad for you.

Which Foods Should I Avoid? By now the answer to the question, “Which Foods Should I Avoid?” is clear. Avoid sodas, sugar-sweetened beverages and processed foods (The term processed foods includes convenience foods, junk foods, and most sweets).

What Does This Mean To You?

Questioning ManNow that we are clear on which foods you should avoid, let’s look at the flip side of the coin. Let’s ask, “Which foods should you include in your diet?

As I said at the beginning of this article, “We have 5 food groups for a reason”. We should consider whole foods from all 5 food groups as healthy.

Of course, each of us is different. We all have foods in some food groups that don’t treat us well. Some of us do better with saturated fats or carbs than others. We need to explore and find the foods and diets that work best for us.

However, whenever we assume one diet is best for everyone, we have crossed the line into nutritionism.

What Does The Bible Say?

Let me start this section by saying that I rely on the Bible for spiritual guidance rather than nutritional guidance. However, as part of our church’s Bible reading plan, I was reading 1 Timothy. A passage from 1 Timothy 4:1-5 leapt out at me. It reinforces the theme of Michael Pollan’s book and seems uniquely applicable to the times we live in.

“The Spirit clearly says that in later times some will abandon the faith and follow deceiving spirits and things taught by demons. Such teachings come through hypocritical liars, whose consciences have been seared as with a hot iron. They…order people to abstain from certain foods, which God created to be received with thanksgiving by those who believe and who know the truth. For everything God created is good, and nothing is to be rejected if it is received with thanksgiving, because it is consecrated by the word of God and prayer.”

Interesting.

The Bottom Line

In this article, I have discussed the concept of “nutritionism” introduced in Michael Pollan’s book “In Defense Of Food”. He defines nutritionism as the belief that we can understand food solely in terms of its nutritional and chemical constituents and our requirements for them.

What Michael Pollan is referring to is taking food constituents like saturated fats, cholesterol, sugar, carbohydrates, polyunsaturated fats, monounsaturated fats, fiber, antioxidants, and probiotics and labeling them as either “good” or “bad”. He points out that when we accept these simplistic labels, we often end up creating foods and diets that are less healthy than the ones we were trying to replace.

At the beginning of the article, I asked the question, “Which Foods Should I Avoid?” I then looked at several foods or food groups we have told to avoid, including saturated fats, red meat, high-fructose corn syrup, sugar, and carbs. When you look at the science behind these recommendations from the lens of nutritionism, you come to two conclusions:

  • We should avoid sodas, sugar-sweetened beverages and processed foods (The term processed foods includes convenience foods, junk foods, and most sweets).
  • Whole foods from all 5 food groups should be considered as healthy.

Of course, each of us is different. We all have foods in some food groups that don’t treat us well. Some of us do better with saturated fats or carbs than others. We need to explore and find the foods and diets that work best for us.

However, whenever we assume one diet is best for everyone, we have crossed the line into nutritionism.

For more details and a bible verse that supports the theme of Michael Pollan’s book and seems uniquely applicable to the times we live in, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Diet And Cancer Risk

What Can You Do To Reduce Your Risk Of Cancer?

Magic WandIt seems like everyone has a magic pill, essential oil, food, or diet that prevents cancer. It doesn’t take a genius to figure out that all the claims can’t be true. No wonder you are confused. You want to know:

  • Which of these claims are true?
  • What can you do to reduce your risk of cancer?

These aren’t trivial questions.

  • Cancer is the second leading cause of death in this country, and some experts predict it will surpass heart disease as the leading cause of death in the near future.
  • While cancer treatments have become much more effective in the past few decades, these treatment successes are often associated with severe side-effects, enormous expense, or both.

That is why I was intrigued by a recent study (FF Zhang et al, JNCI Cancer Spectrum (2019) 3(2): pkz034) on diet and cancer that came from the prestigious Friedman School of Nutrition and Public Policy at Tufts University. This study asked two important questions:

  • How many newly diagnosed cancer cases could have been prevented by changes in the American diet? This is something the authors referred to as the “preventable cancer burden associated with poor diet”.
  • Which foods increased or decreased the risk of cancer? This, of course, is the most useful information for you and me.

Diet And Cancer Risk

Diet And CancerThis study estimated that 80,110 new cancer cases among US adults 20 and older could be primarily attributed to poor diet. While poor diet contributes to many more cancers, the authors of this study felt 80,110 represented the number of cancer cases that were clearly preventable by some simple dietary changes.

While all cancers were affected by diet to some degree, the cancers most affected by poor diet were:

  • Colon cancer (65% of cases)
  • Mouth and throat cancer (18% of cases)
  • Endometrial cancer (4.0% of cases)
  • Breast cancer (3.8% of cases)

When the diet was broken down into individual food groups:

  • Low intake of whole grains was associated with the largest number of preventable cancer cases (35% of cases). This was followed by.
  • Low intake of dairy foods (22% of cases).
  • High intake of processed meats (18% of cases).
  • Low intake of vegetables (16% of cases).
  • Low intake of fruits (10% of cases).
  • High intake of red meat (7.1% of cases).
  • High intake of sugar sweetened beverages (4.0% of cases).

Of the diet-associated cancer cases, the scientists who lead the study estimated that 84% of them represented a direct effect of diet on cancer risk. The dietary factors most likely to directly increase the risk of cancer were:

  • Low intake of whole grains.
  • Low intake of dairy foods.
  • High intake of processed meats.

The scientists estimated that 16% of diet-associated cancer cases were “mediated by obesity”. In layman’s terms, this means that diet increased the risk of obesity and obesity increased the risk of cancer. The dietary factors most likely to increase the risk of obesity-mediated cancers were:

  • High intake of sugar sweetened beverages.
  • Low intake of fruits.

The authors concluded: “More than 80,000 new cancer cases [per year] are estimated to be associated with suboptimal diet among US adults…Our findings underscore the need for reducing cancer burden in the United States by improving the intake of key food groups and nutrients of Americans.”

What Does This Mean For You?

Questioning ManThese findings aren’t novel. Many previous studies have come to the same conclusions. However, many people find these recommendations to be confusing. Should they increase their intake of certain foods? Should they follow some sort of magic diet?

Perhaps we need to get away from the magic food concept. We need to understand that every time we increase one food in our diet, we exclude other foods. We need to step back and look at the overall diet.

Let me break down the recommendations from this study into three categories: foods we should eliminate from our diet, foods we should include in our diet, and foods we should balance in our diet.

Foods we should eliminate from our diet:

  • Sugar Sweetened Beverages. They provide no nutritional benefit, and the sugar in most beverages rushes into our bloodstream and overwhelms our body’s ability to utilize it in a healthy way. This leads to obesity, diabetes, and a host of other health issues.
    • Public enemy number one is sodas. However, this category also includes fruit juices, sweetened teas and energy drinks, and sugary processed foods.
    • This category also includes diet sodas. For reasons we don’t completely understand, diet sodas appear to be just as likely to lead to obesity, diabetes, and heart disease as sugar sweetened sodas. I have discussed the proposed explanations of this phenomenon in a recent issue of “Health Tips From the Professor”.
    • Sugar, however, is not the enemy. Sugar found naturally in fruits and other whole foods enters the bloodstream slowly and is metabolized in healthy ways by the body. I have discussed this in another issue  of “Health Tips From the Professor”. This is what I mean by restoring balance in our diet. Decreasing the sugar intake from sugar sweetened beverages and increasing sugar intake from fruits is associated with a decreased risk of obesity and obesity-related cancers.
  • Processed Meats. The evidence is overwhelming at this point that processed meats directly increase the risk of cancer.
    • If you have trouble completely eliminating processed meats from your diet, my advice is to minimize them and consume them only in the context of an overall healthy diet. Personally, I still consume bacon occasionally as flavoring for a healthy green salad.

Whole GrainsFoods we should include in our diet. I put these in a separate category because Dr. Strangelove and his colleagues have been telling us to eliminate them from our diet, and many Americans are following those recommendations:

  • Whole grains. We can think of whole grains as the underserving victim of the low-carb craze. The low-carb craze is on the mark when it comes to eliminating added sugars and refined grains from the diet. However, eliminating whole grains from the diet may be doing more harm than good. In fact, this and other studies suggest that whole grains are the most effective foods for reducing cancer risk. Why is that?
    • If we assume whole grains are just a good source of fiber and a few vitamins and minerals, it is hard to grasp their importance. We could easily get those nutrients elsewhere.
    • However, we are beginning to realize that whole grains play a unique role in supporting certain species of gut bacteria that are very beneficial to our health. In short, whole grains may be essential for a healthy gut.
  • Dairy Foods. This is another food that has been treated as a villain by Dr. Strangelove and his many colleagues. However, for reasons we don’t completely understand, dairy foods appear to decrease the risk of heart disease and cancer.

Foods we should balance in our diet.

  • Red Meat. Diets high in red meat are consistently associated with a slight increase in cancer risk. The World Health Organization lists red meat as a probable carcinogen, but that has proven to be controversial.
    • Much of the research has centered on why red meat causes cancer. Several mechanisms have been proposed, but none of them have been proven.
    • In contrast, very little consideration has been given to what red meat is displacing from the diet. Diets high in red meat are often low in whole grains, fruits and/or vegetables.
    • Perhaps instead of eliminating red meat from our diets we should be talking about balancing red meat in our diets by consuming less red meat and more whole grains, fruits, and vegetables.

What Can You Do To Reduce Cancer Risk?

American Cancer SocietyYou may have been thinking that 80,110 cases/year represents a small percentage of new cancer cases. That’s because diet is only one component of a holistic cancer prevention strategy. Here is what the American Cancer Society recommends for reducing cancer risk:

  • Avoid tobacco.
  • Limit sun exposure.
  • Achieve and maintain a healthy weight.
  • Eat a healthy diet, with an emphasis on plant foods (Their recommendations are in line with this study).
  • Be physically active.
  • Limit alcohol use.
  • Get vaccinated against HPV.
  • Get regular medical checkups.

Doing any of these things will reduce your cancer risk. But the more of these you can incorporate into your lifestyle, the lower your risk.

The Bottom Line

A recent study looked at diet and cancer risk. The authors reported that 80,110 new cancer cases among US adults 20 and older could be primarily attributed to poor diet.

When the diet was broken down into individual food groups:

  • Low intake of whole grains was associated with the largest number of preventable cancer cases. This was followed in descending order by.
  • Low intake of dairy foods.
  • High intake of processed meats.
  • Low intake of vegetables.
  • Low intake of fruits.
  • High intake of red meat.
  • High intake of sugar sweetened beverages.

The authors concluded: “More than 80,000 new cancer cases [per year] are estimated to be associated with suboptimal diet among US adults…Our findings underscore the need for reducing cancer burden in the United States by improving the intake of key food groups and nutrients of Americans.”

For more details, read the article above. For example, I discuss which foods we should eliminate, which foods we should eat more of, and which foods we should balance in our diet. To add a more holistic perspective, I also discuss the American Cancer Society’s recommendations for reducing cancer risk.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

Health Tips From The Professor